<!DOCTYPE HTML>
<html>

<head>
  <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
  <title>判断语句</title>
  <script type="text/javascript">
    var score = 80; //score变量存储成绩，初值为80
    if (score >= 60) {
      document.write("很棒，成绩及格了。");
    } else {
      document.write("加油，成绩不及格。");
    }
  </script>
</head>

<body>
</body>

</html>